Infections involving the human gastrointestinal tract are extremely common, involving many millions of people on an annual basis. These infections include bacteria, viruses, and fungi, and are responsible for significant illness, morbidity and, in many cases, death. While the invention has utility in destroying microorganisms in various parts of the body, e.g., the stomach, bowel, lungs, peritoneal cavity, urinary tract, etc., it is particularly useful in the treatment of gastrointestinal infections.
It has recently been shown that the most common gastrointestinal infection in the world is due to Helicobacter pylori, a bacterial pathogen that infects the stomach and duodenum. In the United States, for example, Helicobacter pylori is found in approximately 20% of the adult population. It is a chronic gut infection and, once acquired, is notoriously difficult to cure. Most infectious bacteria can be readily destroyed by the human immune system; however, Helicobacter pylori lives in the lumen of the stomach and on the surfaces of the stomach and duodenal cells, making it relatively resistant to a host immune response, even if vigorous. Its position has, however, been taken advantage of in the treatment method and apparatus employed in the present invention.
Helicobacter pylori is typically a silent infection in humans, the majority of the time causing a relatively innocuous gastric inflammation or gastritis. In a significant minority of infected people, however, Helicobacter pylori can cause symptomatic gastritis, gastric ulcer, duodenal ulcer, gastric cancer, and gastric lymphoma. The organism is responsible for approximately 90% of all reported duodenal ulcers, 50% of gastric ulcers, 85% of gastric cancer, and virtually 100% of gastric lymphoma. Millions of Americans have symptomatic gastritis due to Helicobacter pylori or the much more serious entities noted above. Helicobacter pylori is responsible for thousands of deaths in this country due to complicated ulcer disease and cancer, and is considered to be a Class 3 carcinogen by the World Health Organization, in the same class as Benzene and DDT.
The organism is found in all countries in the world, causing the same symptoms, diseases, and deaths, but it is most prevalent in undeveloped countries, presumably due to poor hygiene, contaminated water supplies and crowding. In Peru and other South American countries, for example, the prevalence rate of Helicobacter pylori infection approaches 90%.
There is no vaccine available for Helicobacter pylori and none is anticipated in the foreseeable future, despite years of intensive effort. The only treatment currently available is prolonged and complicated antibiotic regimens involving three or four expensive antibiotics given over a two-week period. Even using a vigorous antibiotic regimen, however, up to 20% of those treated are not cured of their infection.
The antibiotics used are powerful, sometimes not well tolerated, and can cause nausea, an altered taste sensation and diarrhea. Allergic reactions are not uncommon. In addition to the problems of efficacy and side effects, antibiotic resistance to this organism is growing rapidly. Up to 50% of the Helicobacter isolates are now resistant to one or more of the best antibiotics known to cure the infection. This problem of antibiotic resistance is only expected to grow in the future, leading to worsening disease outcomes and an ever-increasing health expense.
Thus, a great need exists for a new, effective, rapid and well-tolerated cure of Helicobacter pylori, a luminal infection of the gut. There also exists a need for a well-tolerated and effective treatment for debilitating or killing microorganisms with as little intrusion as possible in other body cavities, such as the bowel, lungs, peritoneal cavity or urinary tract.